Chronic pain is a serious concern that disproportionately affects Veterans compared to the general public; Veterans are diagnosed with CP at particularly high rates (47 ? 56%) with a 40% greater rate of severe pain than non-Veterans. Veterans with chronic pain face numerous negative functional outcomes, including decreased ability to complete daily work activities, less social support from and closeness with family members, increased chronic health conditions (e.g., cancer, heart disease), and higher mortality compared to Veterans without chronic pain. Given these concerns, there is an urgent need for innovative and integrative approaches for non-medical pain self-management management. Despite the critical importance of effective pain self-management programs, many Veterans with CP do not engage in pain self-management programs. In order to improve Veterans? quality of life, it is important to develop and evaluate innovative, accessible, evidence-based interventions for managing CP. One approach with over twenty years of efficacious treatment for chronic pain is Acceptance and Commitment Therapy for Chronic Pain (ACT-CP). ACT is a well-established VA-approved approach to chronic pain management, and focuses on committing to behavior change that reflects personal values, leading to significant improvement in life functioning. ACT- CP is associated with substantial improvements in social/work functioning and decreased pain-related medical visits, as long as three years following treatment. For adults with chronic pain, technology-assisted ACT treatment leads to reduced self-reported pain levels and improved health via changes in value-aligned behaviors and mindfulness. The use of interactive technology-assisted ACT treatment is acceptable and efficacious; however, no ACT for chronic pain online treatment exists for Veterans. We thus propose a three-phase development, intervention usability and feasibility, and RCT pilot to create a virtual ACT intervention for CP (VACT-CP) for Veterans. VACT-CP will utilize a personalized, social interface to address pain-related distress and functional difficulties of chronic pain (e.g., avoidance, reactivity), using an online Embodied Conversational Agent (ECA) that will walk Veterans through eight weeks of treatment. Studies suggest that the use of such ECAs can increase online-treatment motivation and feedback, resulting in increased treatment compliance and utilization, physical functioning (e.g., increased physical activity and diet fidelity), and client-goal achievement. The primary outcomes for this project will be to (1) develop the VACT-CP user system using feedback from mental health and other clinical professionals treating chronic pain (n = 10), (2) pilot the usability and feasibility of the through iterative usability development and Veteran feedback (n = 12 - 15), and (3) explore the impact of the VACT-CP system in terms of user- experience, functional outcome improvement, and quality of life measures (n = 40).